1. Field of the Invention
The present invention relates generally to hinging systems and, more particularly, to a hinging system and cover assembly for a railroad hopper car which permits each cover to be used with any of a plurality of different hopper car constructions.
2. Discussion of the Prior Art
Since the inception of the covered hopper car in the 1920's, the different manufacturers of railroad hopper cars have made numerous hopper car designs having different lengths and types of hatch openings each requiring a specific hatch cover construction, making it impossible to define a hatch cover having a standard length or hinge type. For example, different trough hatch lengths, widths, and hinge pin to coaming distances, as well as different hinge pin diameters, and different latching systems used with the trough hatches, are among the several variables existing in hatch covers used with known hopper cars.
However, known trough hatch arrangements generally fall into two broad groups; troughs having a 20" width, and troughs having a 24" width. Typically, troughs having a 24" width are designed in several lengths, two of which are more widely used than the rest. These lengths are 10'-11 11/16"and 12'-113/4". In addition, the hinge pins typically employed to connect hatch covers to the hinge pin brackets of these 24" width troughs are displaced vertically from the upper edge of the coaming of the trough hatch by one of five different distances; +13/16", +1/2", even, -1/4"and -11/4". When a hopper car is built utilizing a 24" width and hinge pin brackets having one of the above-mentioned hinge pin-to-coaming distances, the hatch cover or covers to be used on the car are fitted with cover brackets that align the cover with the hopper car hinge pin brackets. Thus, each cover may only be used with a single hopper car arrangement, and it is necessary to provide as many different hatch cover assemblies as there are hopper car arrangements.
As an attempted solution to this problem, it has been proposed that each hinge bracket employed with a hatch cover be made reversible relative to the hatch cover so that the hinge bracket may be used to accommodate either of the five different arrangements mentioned above. Previously, however, with normal construction, it would be necessary to remove the entire hinge bracket assembly should it be determined that another size of hinge bracket is required, which can result in the need for a completely new cover assembly where, e.g. the brackets are riveted or otherwise permanently fastened to the hatch cover.
Where 20" width trough hatch arrangements are used, six lengths are commonly employed. These lengths are 7'-113/4", 8'-33/8", 9'-6", 10'-73/8", 12'-43/8" and 11'-11 3/16". The 20" hatch covers are attached to the hopper cars using hinge pins that have a vertical hinge pin-to-coaming separation of either +1/16" or -11/4". Additionally, one of two different locking systems are employed with the 20" width constructions to latch the covers to the hopper cars. Each of these locking systems includes a locking mechanism unique to that system and further requires a bracket which must be incorporated in the cover assembly to mate properly with each unique locking system on the hopper car. Thus, not only must the cover itself cooperate with the hinge pin brackets of the hopper car, but the locking system must also cooperate therewith.
In view of the many different variables existent in the field of hopper car covering assemblies, it would be desirable to provide a hatch cover assembly that may be used on any of several car constructions in order to reduce the amount of inventory that a supplier must carry to satisfy the needs of the industry.